/*
 * Copyright 2017 ~ 2025 the original author or authors. <wanglsir@gmail.com, 983708408@qq.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.wl4g.devops.dguid.baidu.utils;

import java.util.concurrent.atomic.AtomicLong;

/**
 * Represents a padded {@link AtomicLong} to prevent the FalseSharing problem
 * <p>
 * 
 * The CPU cache line commonly be 64 bytes, here is a sample of cache line after
 * padding:<br>
 * 64 bytes = 8 bytes (object reference) + 6 * 8 bytes (padded long) + 8 bytes
 * (a long value)
 * 
 * @author yutianbao
 */
public class PaddedAtomicLong extends AtomicLong {
	private static final long serialVersionUID = -3415778863941386253L;

	/** Padded 6 long (48 bytes) */
	public volatile long p1, p2, p3, p4, p5, p6 = 7L;

	/**
	 * Constructors from {@link AtomicLong}
	 */
	public PaddedAtomicLong() {
		super();
	}

	public PaddedAtomicLong(long initialValue) {
		super(initialValue);
	}

	/**
	 * To prevent GC optimizations for cleaning unused padded references
	 */
	public long sumPaddingToPreventOptimization() {
		return p1 + p2 + p3 + p4 + p5 + p6;
	}

}